Novel composite right/left-handed leaky-wave antennas

In this paper several novel composite right/left-handed (CRLH) leaky-wave (LW) antennas are discussed. In each of the four cases both left-handed and right-handed properties of the structure allow the designers to achieve extraordinary phenomena. The first antenna is a CRLH LW antenna that can perform radiation angle scanning along with beamwidth controlling at a fixed frequency by using varactor diodes. The second antenna is a LW array antenna that can perform 2-D frequency-controlled beam-steering. Next, we discuss a common-/differential-mode LW antenna which can operate in a left-handed (LH) mode under differential-mode operation. On the other hand, the common-mode is in the cut-off region of this antenna which makes it well suitable for integrated mixer application. The next structure is a conformal CRLH LW antenna that has been dispersion engineered to perform similar radiation characteristics as a planar version in terms of the radiation beamwidth. Finally we discuss two active CRLH LW antennas, one is used for beam-shaping and the there one is a integrated CRLH LW antenna with distributed amplifier (DA).